1. Field of Invention
This invention pertains to optical switches. More particularly, this invention pertains to an optical switching assembly including an array of optical switches with a spare input available to replace any of the optical inputs in the array and to optical switching assemblies that include 1×N and N×1 switches.
2. Description of the Related Art
Optical signals are transmitted over fiber optic cables. There is a large demand to send optical signals over great distances without sacrificing data integrity. In order to achieve this goal, it is common practice to use repeaters at intermediate distances. Repeaters typically convert the optical signal into an electrical signal and then back into another optical signal, which is sent over the next length of fiber optic cable.
It is desirable to maximize the up-time of fiber optic systems. One common method to achieve maximum up-time is to have spare optical transmitters standing by that can be switched to replace failed transmitters. Typically, there is one spare for each transmitter, which results in a large amount of unused, standby capacity.
Fiber optic cables have a minimum bend radius which is large relative to the cable diameter. Accordingly, routing of fiber optic cables oftentimes determines the size and layout of fiber optic equipment, which is commonly rack mounted with input and output connections accessible from a front panel. In order to accommodate high density requirements, it is desirable to minimize the size of fiber optic equipment.
It is also desirable to minimize attenuation of the optical signals in optical equipment. A factor that affects attenuation is the dimensional stability of the components in the optical equipment. The optical signal from an fiber optic cable has a small size and small changes in alignment, for example, due to changes in temperature, may cause attenuation of the optical signal. Further, it is desirable to operate optical equipment over a wide temperature range, which is at odds with the desire to minimize attenuation.